The present invention relates to an additive for lubricating oils, a lubricating oil composition containing the same, various low friction slide members, an antifriction bearing and a slide bearing. More specifically, the present invention relates to an additive for lubricating oils used for a part to be lubricated in which a low friction slide members such as an inorganic material for being coated, a lubricating oil composition containing the same, various low friction slide members which have a diamond-like carbon film at least on a part of a slide part and in which the above lubricating oil composition is used for a sliding surface, an antifriction bearing and a slide bearing.